A relevant detailed background of respirators of the prior art is given in U.S. Pat. Nos. 4,641,645-4,856,508 and 4,945,907.
A common problem in limited use or disposable breathing respirators of the prior art is that the chin portion of the respirator tends, due to the force pulling the respirator against the wearer's face, to slip under the wearer's chin. This results in the undesirable situation where the interior of the respirator shell touches the lips of the wearer. It also results in the periphery of the respirator shifting downward and, therefore, in some cases resulting in leakage between the periphery of the respirator and the wearer's face. In order to overcome such tendency for downward shifting of the respirator on the wearer's face, an excessive force is applied on the top portion of the respirator in order to increase the frictional resistance between the face of the wearer and the periphery of the respirator. The application of such force, however, makes it uncomfortable for the wearer to continue to wear the respirator for extended periods of time.
Accordingly, there is a need in the art for limited use or disposable respirators that are more comfortable, inexpensive, flexible and light-weight which can rest securely against the wearer's face, resist slipping under the chin of the wearer and achieve an air-tight seal around the periphery of contact with the wearer's face under a very low magnitude pulling force. The breathing mask of the present invention addresses and meets the above needs.